Apparatus for making concrete blocks



Feb. 3, 1970 D. D. scHwl-:LL-:NBACH 3,492,704

APPARATUS FOR MAKING CONCRETE BLOCKS y Filed June l5, 1967 3 Sheets-Sheet 2 Q E w, 4770/915451 Feb. 3, 1970 D. D. SCHWELLENBAC'H APPARATUS FOR MAKING CONCRETE BLOCKS y 3 Shets-Sheet 3 Filed June l5 1967 om T. N E V m United States Patent O 3,492,704 APPARATUS FOR MAKING CONCRETE BLOCKS Donald D. Schwellenbach, 124 S. Filmore, Pierre, S. Dak. 57501 Filed June 15, 1967, Ser. No. 646,373 Int. Cl. F2613 3/18 U.S. Cl. 25-133 7 Claims ABSTRACT F THE DISCLOSURE A high capacity apparatus for curing concrete building blocks comprising a kiln having open front and rear ends and having a plurality of support elements therein to dene a plurality of passages arranged in horizontal rows, one above the other. .A vertically shiftable horizontally oriented infeed conveyor mechanism positioned transversely of and closely adjacent the front end of the kiln for conveying uncured blocks to the kiln, and a vertically shiftable horizontally oriented removal conveyor mechanism positioned transversely of and closely adjacent the rear end of the kiln for receiving cured blocks from the kiln. Means for simultaneously shifting the conveyor mechanisms vertically and a block shifting mechanism carried by the infeed conveyor mechanism for successively feeding uncured blocks, one at a time into the passages.

This invention relates to an apparatus for making concrete building blocks, and more specifically to a high capacity operation for curing concrete blocks.

An object of this invention is to provide a high capacity apparatus system, of simple and inexpensive construction and operation, for curing concrete building blocks, including means for conveying uncured concrete blocks from a block making machine to a curing kiln where the blocks are urged into and through the kiln with provision for continuous removal of the blocks from the kiln, whereby the apparatus system is especially adapted for a continuous line operation.

A more specic object of this invention is to provide a novel high capacity apparatus for curing concrete building blocks including a kiln and adjustable infeed and removal conveyors for conveying uncured blocks to and removing cured blocks from the kiln, and block shifting means for urging the blocks from the infeed conveyor into and through the kiln so that cured blocks are successively urged upon the removal conveyor for transfer to a convenient stock pile or the like.

These and other objects and advantages of this invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views, and in which:

FIG. 1- is a perspective view of the novel concrete block curingy apparatus;

FIG. 2 is a plan view of a portion of the apparatus taken approximately along line 2-2 of FIG. 1 and illustrating the means for vertically shifting the conveyor mechanism;

FIG. 3 is a cross-sectional view on an enlarged scale taken approximately along line 33 of FIG. 2 and looking in the direction ot the arrows;

FIG. 4 is a cross-sectional view taken approximately along line 4-4 of FIG. 1 and looking in the direction of the arrows;

FIG. 5 is a perspective view on an enlarged scale of the block shifting means; and

3,492,704 Patented Feb. 3, 1970 ice FIG. 6 is a perspective view diagrammatically illustrating certain parts of the block shifting means illustrated in FIG. 5. v

Referring now to the drawings, and more specifically to FIG. 1, it will be seen that one embodiment of a high capacity apparatus for making concrete `block and designated generally by the reference numeral 10 is there shown. This apparatus includes a block making machine 11 of conventional constructionk and operation, which is operable to mold concrete blocks B in a well-known manner. It will be noted that the concrete blocks B, which are molded in the block making machine 11, will be positioned upon a plate P, preferably formed of a suited rigid metallic material, such as steel or the like. The uncured blocks B are transferred from the block making machine 11 to a curing kiln 13 by an infeed conveyor mechanism 12. The curing kiln 13, as best seen in FIGS. l and 4, is of generally rectangular configuration and includes a top wall 14 and opposed sidewalls 15, and is provided with a floor or bottom wall. The curing kiln has an open front end 16 and an open rear end 17, which intercommunicates the interior of the kiln with the exterior. The kiln is provided with a plurality of vertically extending substantially parallel spaced apart front support posts 18, and a corresponding number of rear posts 19, which extend -between the floor of the kiln and the top wall 14. Each front post 18 is disposed in longitudinal alignment with one of the rear posts 19 and each front and rear aligned pair of posts has a plurality of elongate rigid support elements or tracks 20 affixed thereto and eX- tending therebetween. It will be noted, that the tracks 20, which are rigidly secured to each post, are vertically spaced apart and are horizontally oriented, and in the embodiment shown are of angle cross-sectional construction. Each track is disposed in horizontal alignment with the adjacent track on the adjacent post, so that a plurality of passages 21 are dened, which extend completely through the kiln from the front end to the rear end thereof. It will be noted, that these passages are arranged in horizontal rows and these rows are arranged in vertical relation with respect to each other. 'Each passage is adapted to support the support plates P upon which the uncured concrete blocks are positioned.

In this regard, it will be noted that each support plate P is adapted to support a pair of concrete blocks, although support plates for accommodating single concrete blocks or a plurality of blocks may also be provided. It will also be noted, that each support plate P has width and length dimensions which are slightly greater than the length and width dimensions of the pair of concrete blocks positioned thereupon, so that the marginal edge portions of the support plate project beyond the vertical edges of the uncured concrete blocks seated thereupon.

The infeed conveyor mechanism 12 comprises a sectional conveyor which includes a first frame section 23 and a second frame section 24 which are pivotally connected together. The first frame section 23 includes a pair of side walls 25, which are laterally spaced apart and rigidly interconnected by suitable transverse brace members 2'6. The second frame section 24 also includes a pair of side walls 27, which are rigidly interconnected by transverse brace members 28. It will be noted, that the side walls 25 of the first frame section 23 are pivotally connected at one of their `respective ends by a pivot 29 to the sidewalls 27 of the second frame section.

The second frame section 24 is vertically shiftable on a conveyor support structure 31 for vertical shifting movement relative to the open front end of the kiln 13. To this end, it will be noted that each of the side walls 27 has vertical sleeves 30 affixed to opposite ends thereof and these sleeves are positioned on substantially tubular vertically oriented guide rods 32 of the conveyor support structure 31. The upper and lower ends of adjacent guide rods 32 are rigidly interconnected by upper and lower transverse end frame members 33, as best seen in FIG. 1. It Will be noted, that the upper end frame members 33 are rigidly interconnected by longitudinal frame members 34, the purpose of which will be more fully described hereinbelow.

A pair of elongated endless conveyor chains 35 are trained about sprockets 36, which are mounted on shafts 37, but are journalled in the side walls of the first and second frame sections 23 and 24, respectively. The upper runs of the chains 35 support the plates P and convey the same into position for introduction into the kiln 13. It is pointed out that drive means are provided for driving one pair of the sprockets 36 and this drive means cornprises an electrical motor, having suitable drive connections with the driven sprockets. Although not shown in the drawing, the first frame section 23 and that portion of the endless conveyor chains 35 supported thereon will be positioned closely adjacent the outlet of the block making machine 11, to receive concrete blocks therefrom and to convey the blocks into position for introduction into the kiln 13. The second frame section 24 is positioned in close proximity to the open front end of a kiln 13 and extends transversely of the kiln throughout the width thereof. This second frame section 24 is horizontally oriented, even though it is vertically shiftable relative to the kiln.

Referring now to FIGS 1, 2 and 3, it will be seen that means are provided for vertically shifting the infeed conveyor mechanism 12, and this means comprises a piston and cylinder unit including a hydraulic cylinder 39 having a piston axially movable therein to which is connected a piston rod 40, which extends axially outwardly `from the cylinder 39. One end of the cylinder 39 is connected by a bracket 41 to a cross brace 42, which extends between and is rigidly affixed to the longitudinal frame members 34 of the conveyor support structure 31.

The front end of the cylinder 39 is also secured to a cross brace 43 by a bracket 44 and a pair of elongate spaced apart substantially parallel channel-shaped track members 45 extend between and are rigidly secured to the cross brace 43 and one of the end transverse members 33. `It will be noted, that the track members 45 are positioned interiorly of and spaced from the longitudinal frame members 34. The free end of the piston rod 40 has a cross member 46 secured thereto and slide blocks 47 are secured to the cross member 46 and are positioned in the track members 45. A plurality of cables 48 each have one end secured to the cross member 46 and these cables are thereafter trained about pulleys 49, which are revolvably mounted on the cross brace 42. These cables are thereafter trained about vertically oriented pulleys 50 located at opposite ends of the transverse frame members 34 and the ends of these cables 48 are secured to suitable apertured brackets 51 carried by the sleeves 30. Extension and retraction of the piston rod 40` causes the cables 48 to be progressively tensioned or relaxation of the tension to thereby cause raising and lowering of the infeed conveyor mechanism 12. It will also be noted, that the cross member 46 has a pair of cables 52 connected thereto, and these cables are trained over a pair of pulleys S3 mounted on a support plate or bracket 54, secured to one of the end frame members 34. These cables are then extended rearwardly and are connected with a removal conveyor mechanism for shifting this conveyor mechanism vertically simultaneously with shifting movement of the infeed conveyor mechanism.

This removal conveyor mechanism 55 is similar in construction to that part of the sectional infeed conveyor mechanism that is carried by the second frame section 24. The removal conveyor mechanism includes a conveyor support frame 56 comprised of a pair of sidewalls 57 connected by suitable cross braces 58. The sidewalls have suitable sprockets thereon about which are trained a pair of driven endless conveyor chains 59. A conveyor support structure y60 is also provided and is identical in construction to the conveyor support structure 31 and includes a plurality of vertical guide rods 61 interconnected at their upper and lower ends by transverse end frame members 62, the upper end frame members being rigidly interconnected by suitable longitudinal frame members (not shown). The sidewalls 57 have sleeves at opposite ends thereof, which are positioned around and are slidable upon the guide rods 61 in the manner of the infeed conveyor mechanism 12.

The cables 52, which extend rearwardly from the front conveyor support structure 31 are trained about pulleys 63 mounted on the end frame member 62 and extend downwardly therefrom and are connected to cable type slings 64, which are secured to opposite ends of the sidewalls 57. Thus, it will be seen, that when the infeed conveyor mechanism 12 is raised or lowered, the removal conveyor mechanism 55 will be simultaneously raised and lowered. Therefore, the infeed and removal conveyor mechanisms are maintained at the same level as each other.

,Means are provided for releasably locking the infeed and removal conveyor mechanisms in an adjusted vertical position. Referring again to FIGS. 2 and 3, it will be seen that this locking means includes a pair of elongate serrated locking members 65, each having a plurality of notches I66 therein and each being rigidly secured to the upper surface of one of the track members 45. The cross member 46 has a pair of arms 66 rigidly secured thereto and projecting upwardly therefrom adjacent opposite ends of the cross member. It will be noted, that the arms 66 are of generally angle shaped configuration and a rock shaft 67 extends between these arms and is journalled thereon. The rock shaft 67 has a pair of elongate latch element arms 68 secured thereto for movement therewith.

Means are provided for shifting the latch elements 68 into and out of engaging relation with the locking member 65 and this means includes a solenoid actuator 69 mounted on one of the arms 66 and having its plunger 70 secured to the associated latch element 68. Electrical conductors 71 interconnect the solenoid to a source of electrical current and a suitable manually or automatically operable control swtch (not shown) is interposed in the circuit whereby an operator may very easily shift the latch elements into or out of engaging relation with respect to the locking members.

Means are also provided for pushing or urging the blocks from the infeed conveyor mechanism successively into one of the kiln passages 21 and this block shifting means, designated generally by the reference numeral 72 comprises a generally rectangular shaped support or frame structure 73, which includes longitudinal frame members 74 interconnected by vertical frame members 75 and transverse frame members 76, as best seen in FIGS. 1, 5 and 6. Rollers 77 are provided on the vertical frame members 75 and engage the upper surface of the side walls 27 of the second frame section 24. It will be noted, that this second frame section 24 projects through the frame structure 73 interiorly of the vertical frame members and between the upper and lower transverse frame members. The rollers 77 permit the frame structure 73 5o be moved longitudinally of the second frame section The block shifting means 72 also includes a relatively large hydraulic piston and cylinder unit comprised of a cylinder 78, having a piston movable therein to which is connected a piston rod 79, which projects axially from the cylinder. The outer end of the piston rod has a pressure plate 80 secured thereto, and it will be noted that this pressure plate is vertically oriented. Elongate mounting straps 81 are secured to the rear end of the cylinder 78 and are secured to the frame structure 73 to rigidly support the cylinder on the frame structure. Brackets 82 are secured to the forward end of the cylinder 78 and are mounted on a longitudinal frame member 74, so that the cylinder is supported rigidly in a horizontal position. Extension of the piston rod 79 from a retracted position will extend the piston rod transversely of the frame structure 73.

Means are provided for elevating each plate P that has concrete blocks thereon from supported relation on the endless conveyor chains 35 into position for entry into one of the passages 21 of the kiln 13'. This block elevating or lifting means comprises a generally rectangular shaped frame 83, which is positioned interiorly of the frame structure 73. This rectangular frame 83 is dimensioned to pass between the endless conveyor chains 35 and has a pair of upstanding spaced apart guide rods 84, rigidly axed thereto and projecting upwardly therefrom adjacent one side thereof. Suitable pillow bearings 85 are mounted on the frame Structure 73, adjacent one end thereof. In the embodiment shown, these pillow bearings 85 are mounted on the frame structure 73 on the most distal exterior end portion of the frame structure 73, as viewed in FIG. 5.

A hydraulic piston and cylinder unit is provided for vertically shifting the rectangular frame 83 and this unit includes a cylinder 85 which is secured by a bracket 85a to the frame structure 73. The cylinder 86 has a piston movable therein and a piston rod 87 is secured to the piston and projects exteriorly of the cylinder and is secured to a relatively rigid rod 88, which extends between and is connected with the guide rods 84. It will therefore be seen that when the piston and cylinder unit is extended and retracted, the frame 83 will be raised and lowered.

A lever 89 is pivotally mounted intermediate its ends upon the frame structure 73 adjacent one corner thereof by a pivot I90, as -best seen in FIGS. 5 and 6. This lever has one end pivotally connected to one of the guide rods 84 by a pivot 91 and has its other end pivotally connected by a pivot 92 to the operator arm 93 of a valve mechanism 94. This valve mechanism 94 is disposed in tlow controlling relation with respect to a pair of conduits 95, which are connected to the double acting cylinder 78 and which are also connected to a source of hydraulic liquid under pressure. Therefore, when the rectangular frame 83 is elevated, the valve mechanism 94 will be actuated to extend the piston rod 79. A micro-switch 96 having a switch actuating element 97 is mounted on the frame structure 73 adjacent one end thereof, asbest seen in FIG. 5, so that when a plate P strikes the switch actuator element the micro-switch will be closed, which in turn controls a solenoid valve (not shown) that operates the piston and cylinder unit to thereby extend the piston rod 87. When the micro-switch element is opened, the piston rod 87 will be retracted.

Means are provided for releasably locking the frame structure 73 to the kiln and this means comprises a pair of hooks or locking elements 98, each being secured to one of a pair of shafts 99, which in turn are journalled in sleeves 100 that are secured to the frame structure 73. -It will be noted that the hooks l98 project from the frame structure 73 when the hooks are in the extended locking Iposition for engagement with a pair of posts 18. Suitable keeper straps are provided for retaining the hooks 98 in horizontal relation, and it is pointed out that these hooks are swingable between an extended position, as illustrated in FIG. 5, to a retracted position, wherein the hooks rotate with their associated shaft from the extended position towards each other.

The means for moving the hooks between locked and unlocked positions comprises a hydraulic piston and cylinder unit including a cylinder 102, which is mounted on the frame structure 73 by a bracket 103, and which has a piston movable therein to which is secured a piston rod 104. 'Ihe free end of the piston rod 104 is pivotally connected to a pair of links 105, as |best seen in FIG. 5. Each of these links is pivotally connected to a crank arm 106, each crank arm being pivotally mounted on the frame structure 73 by a pivot 107. It will therefore be seen that when the piston and cylinder unit is extended land retracted, the hooks 98 will be shifted between opened and closed positions. All of the hydraulic piston and cylinder units will be connected to a suitable source of hydraulic fluid under pressure and it is pointed out that operation of the hydraulic and piston unit for controlling the hooks 98 will be manually controlled in the embodiment shown.

During operation of the device, blocks will be continuously made and discharged from the block making machine 11 upon the infeed conveyor mechanism 12. A pair of such blocks will be positioned upon each support plate P and each plate will be moved by the conveyor chains 35. The second frame section 24 will be positioned into discharge blocks into a selective kiln passage 21. To this end, the block shifting means 72 will be positioned in predetermined relation longitudinally of the second frame section 24 and the latter will be disposed in predetermined position with respect to the conveyor support structure 31.

The plate P with the pair of concrete blocks B mounted thereon will pass interiorly of the frame structure 73 until the blocks strike the micro-switch actuator element 97 of the micro-switch 96. This actuates a control solenoid valve to thereby extend the piston rod 87 and to elevate or raise the rectangular frame 83 from a lowered position. When the rectangular frame is in the lowered position, it will be positioned interiorly of the frame structure 73 but below the plate P, which is mounted on the conveyor chains 35. As the rectangular frame 83 is raised, it will engage and lift the plate P with the concrete blocks thereon from the conveyor chains 35 until the lever 89 operates the valve mechanism 94 to thereby extend the piston rod 79. The pressure plate 80 will engage the edges of the plate P and Will push the plate with the blocks mounted thereon into one of the kiln passages 21.

As the concrete blocks are urged into the preselected passage 21, the plate P supporting the blocks will be moved out of engaging relation with respect to the micro-switch actuator element 97. The piston rod 87 will be extended until the knob 121 on the rear end of a guide rod 120 on the piston rod 79 strikes the actuator element of a solenoid control valve (not shown) for retracting the piston rod 79.

It is pointed out that the guide rod is slidable in a sleeve 122 which is mounted on brackets 82, the front end of the rod 120 being rigidly secured to the pressure plate 80.

When it is desirable to change the position of the block shifting means, a manual switch is operated to control the solenoid valve, that operates the piston and cylinder unit whereby the piston rod 104 is retracted. The hook 98 will -be moved out of engaging relation with respect to a pair of the posts 18 and the block shifting means may then be shifted longitudinally of the second frame section 24 into a new desired position.

When it is desirable to change the position of the second frame section relative to the conveyor support structure 31, suitable switch means are operated, which control operation of a solenoid valve for the cylinder 39 and the piston rod 40 will be extended or retracted to properly position the second frame section at the desired elevation. During movement of the infeed conveyor mechanism, the removal conveyor mechanism 55 will be simultaneously moved. A separate switch and circuit will be provided for operating the solenoid actuator 69 so that the solenoid must be selectively energized or de-energized prior to raising or lowering the infeed conveyor mechanism and the removal conveyor mechanism.

It is pointed out that -blocks may be successively introduced into a selected passage until the passage is completely filled and thereafter when an additional block is urged into such a passage, a cured block will be forced outwardly of the opened rear end of the kiln. The removal conveyor mechanism 55 is provided with means for receiving each pair of cured blocks B on a support plate as they are ejected or urged outwardly of the kiln. To this end, a carriage 108 provided with rollers 109 is movable along longitudinally extending tracks 110, which are secured to the sidewalls 57 of the removal conveyor mechanism S. The carriage 108 has a plurality of link arms 111 pivotally connected thereto and these link arms are also pivotally connected to a platform 112, which is swingable between collapsed and erect positions. The platform, carriage and link arms define a parallelogram linkage. It will be noted, that when the platform is in the collapsed position, it is positioned upon the carriage and is spaced below the conveyor chains 59. However, when the platform is in the erect position, it is dimensioned to pass between the conveyor chains and at a high level relative thereto to receive the plate P with a pair of blocks thereon, whereby upon retraction, the plates with the cured blocks thereon will be positioned upon the conveyor chains.

Means are provided for shifting the platform between erect and collapsed positions, and this means comprises a hydraulic piston and cylinder unit, including a cylinder 114 having a piston movable therein, which has a piston rod 11S connected thereto. The cylinder 114 is pivotally connected to the carriage, while the piston rod is pivotally connected to the platform. Thus, extension and retraction of the piston and cylinder unit shifts the platform between erect and collapsed positions. The piston and cylinder unit will be connected to a suitable source of hydraulic fluid under pressure, and it is pointed out that the platform 112 will be shifted to the erect position when the piston rod 79 is extended. With this arrangement, the platform will be raised when a plate P having blocks thereon is urged into one of the passages 21.

Cured concrete blocks are discharged from the removal conveyor upon an apron conveyor 116, which is positioned adjacent one side of the kiln in the embodiment shown, and these cured blocks are moved and stock piled in a well-known manner. An apron-type return conveyor 117 is disposed in cooperating relation with the apron conveyor 16 and receives the plate P therefrom to return the plates to the block making machine 11.

The interior of the kiln is heated by steam which is introduced by suitable apparatus well known in the art. By utilizing only stationary support elements or tracks 20 within the kiln for supporting the blocks, maintenance problems with respect to the kiln are substantially reduced. Conventional curing kilns which use interior conveyor systems, -such as chain conveyors, rollers and the like, that are exposed to steam, are constantly faced with maintenance problems. By using stationary tracks and an exteriorly located block shifting means, there are very few mechanisms that are subjected to corrosion and damage by exposure to steam.

The kiln curing apparatus described hereinabove provides a means for high capacity curing of uncured concrete blocks and obviates the necessity of the conventional equipment now associated with the transfer of the uncured blocks from the block making machine to the kiln. This conventional equipment includes fork lift vehicles and the like, which requires considerably more labor than the present apparatus and also involves an interrupted type operation. The present process minimizes the use of manpower, therefore effecting a substantial saving in labor.

It will therefore be seen from the foregoing description, that I have provided a novel curing apparatus for concrete blocks and the like, which is not only of simple and inexpensive construction and operation, but an apparatus which functions in a more efficient manner than any heretofore known comparable apparatus.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various parts without departing from the scope of my invention.

What is claimed is:

1. Apparatus for curing concrete blocks comprising a drying and curing kiln having an open front end and an open rear end, the uncured concrete blocks being `supported upon plates,

a plurality of elongate, similar, spaced apart parallel support elements mounted in said kiln, said support elements having length dimensions corresponding to the fore and aft dimensions of said kiln and defining a plurality of generally fore and aft horizontal pas- `sages extending completely through the kiln and arranged in a plurality of horizontal rows disposed one above the other,

an elongate infeed conveyor mechanism positioned in close proximity to and extending transversely of the front end of said kiln and adapted to support and convey blocks transversely of the kiln and to dispose uncured blocks in a position for entry into one of said passages, said conveyor mechanism being vertically shiftable relative to said kiln,

plate shifting mechanism mounted on said infeed conveyor mechanism and being vertically shiftable with said infeed conveyor mechanism and longitudinally :shiftable relative to said infeed conveyor mechanism, said plate shifting mechanism being operable to urge plate containing uncured blocks one at a time into the front end of a selected passage of the kiln to progressively fill the passage and to successively forcibly urge plates containing cured blocks one at a time from the passage at the open rear end thereof,

an elongate removal conveyor mechanism mounted in close proximity to and extending transversely of the open rear end of said kiln and adapted to convey plates containing cured blocks transversely of the kiln, said removal conveyor mechanism being vertically shiftable relative to said kiln, conveyor shifting means mechanically connecting said infeed and removal conveyor mechanisms and being operable to simultaneously vertically shift said infeed and removal conveyor mechanisms, and maintaining said conveyor mechanisms at the same vertical level,

and power means connected lwith said mechanical conveyor shifting means for operating the latter.

2. The apparatus as dened in claim 1 wherein said plate shifting mechanism comprises a mounting frame mounted on said infeed conveyor mechanism for horizontal longitudinal shifting movement relative thereto, a generally horizontally oriented piston and cylinder unit mounted on said mounting frame and being extensible and retractable in a direction transversely of the conveyor mechanism for urging plates containing uncured blocks into a selected passage of said kiln.

3. The apparatus as defined in claim 2 wherein said plate shifting mechanism includes a block elevating mechanism mounted on said frame structure and being vertically shiftable relative thereto between a lowered position and an elevated position, said block elevating mechanism when shifted to said elevated position engaging a plate containing an uncured block on said infeed conveyor mechanism and elevating the same therefrom into position to be engaged by said piston and cylinder unit.

4. The apparatus as defined in claim 1 and releasable locking means including a first locking element connected with said power means, a second locking element being releasably engageable by said nst locking element for releasably locking said conveyor mechanisms in an adjusted position.

5. The apparatus as defined in claim 2 and releasable locking means on said mounting frame of said plate shifting mechanism for releasably locking the latter in an adjusted position longitudinally of said infeed conveyor mechanism.

6. The apparatus as defined in claim 1 wherein said conveyor shifting means comprises a cable connected with said infeed and removal conveyors, and said power means include a uid pressure motor connected with said cable for selectively tensioning and relaxing said cable to simultaneously vertically shift said conveyor mechanisms.

7. The apparatus as delined in claim 1 and a carriage mounted on said removal conveyor mechanism for vertical movement therewith and longitudinal movement relative thereto, said carriage receiving plates containing cured blocks from the kiln and transferring the plates References Cited UNITED STATES PATENTS 2/ 1900 Jones.

5/ 1910 Cole.

1/1949 Hanson 214-164 4/1950 Gelbman 25-133 8/1966 Thomas 214-164 9/1966 Waite 214-164 X 6/1967 Danielsson et al. 214-16.4

WILLIAM J. STEPHENSON, Primary Examiner U.S. C1. X.R.

containing the cured blocks to the removal conveyor 15 25-2, 142; 214-164 mechanism. 

